This proposal is for The Ohio State University, College of Optometry (TOSU) to serve as one of the five VIP Participating Clinical Centers in the Vision In Preschoolers (VIP) Study. The VIP Study is a prospective, clinical study designed to develop an effective and efficient battery of screening tests to identify those 3- and 4-year~old Head Start children in need of further vision care for amblyopia, strabismus, and/or significant refractive error, that are the prevalent, significant vision disorders of early childhood. To accomplish these goals, a battery of screening tests will be administered to at least 1,359 3- and 4-year old children enrolled in VIP Affiliated Head Start programs throughout Columbus, Ohio. The battery of tests consists of tests chosen for their design characteristics, validity, and applicability to the preschool population and includes the Massachusetts Visual Acuity Test (MassVat), a form of the Lea symbols visual acuity test at distance, the Random Dot E (RDE) test of stereoacuity, and noncycloplegic autorefraction using the Nikon Retinomax. The battery of tests will be administered at Head Start Sites by Lay People (Head Start parents) which ensures availability of screeners, utilizes persons with a vested interest in benefitting children, and maximizes the applicability of this model to other communities. Each child who fails the screening or is unable, and a randomly selected subset of children who pass the screening, will undergo a comprehensive eye examination at TOSU Clinical Center. The examination will serve as the definitive method, or Gold Standard, for detection of the target disorders. The sensitivity and specificity for detection of the target disorders will be determined for each of the screening battery tests alone, and in combination. This application documents: a) access of TOSU VIP Participating Clinical Center to at least 1,853 children enrolled in Head Start and b) that facilities and personnel are available for conducting vision screenings at the Head Start sites and for conducting Gold Standard Examinations. Complete details of the VIP Study rationale, design, and methods are contained in the VIP Manual of Procedures (MOP), which is submitted with the VIP Study chair application.